An increasing segment of the pallet market are pallet pools, such as the CHEP, which offer companies a pool of refurbished pallets at a set cost and take on the responsibility of maintaining and storing the pallets. Walmart is one of the largest companies to take advantage of this service in an effort to bring down their distribution costs. Distinquished by their blue color, the CHEP north American pallet pool contains around 90 million pallets. They use a standard 48 x 40 perimeter base wood pallet, and are begining to implement Radio Frequency Identification tracking on pallets to allow costumers to keep closer track of shipping.